L-Phosphinothricin

Phosphinothricin (PPT) is an unnatural amino acid with the distinctive structural characteristic of a phosphinic acid moiety. Phosphinothricin is a non-selective and broad-spectrum herbicide. The current phosphinothricin products in the market are usually a racemic mixture with two configurations, the D-type and L-type, of which only the L-phosphinothricin has the herbicidal activity. The utilization of L-phosphinothricin will cut herbicide usage in half, improve the atomic economy, and greatly benefit the environment.

The current industrial synthesis of L-phosphinothricin is mainly via chemical or biotechnological methods. As with the advantages of strict stereoselectivity, mild reaction conditions and high yield, biosynthesis of L-phosphinothricin draws increasing attention.

Action Mechanism as an Herbicide

Glutamine synthetase (GS) is one of the essential enzymes for plant autotrophy. It catalyzes the incorporation of ammonia into glutamate to generate glutamine with concomitant hydrolysis of adenosine triphosphate (ATP) and plays a crucial role in the assimilation and re-assimilation of ammonia derived from a wide variety of metabolic processes during plant growth and development. L-phosphinothricin inhibits the activity of the enzyme glutamine synthetase, leading to a decrease in glutamine and an increase in ammonia which cause the death of the plant (Figure 1)^[1,2].

Fig. 1 Mechanism of action of L-phosphinothricin as a potent inhibitor of glutamine synthetase (GS) in higher plants

Biosynthesis of L-Phosphinothricin

According to the different types of raw materials, there are mainly three biosynthesis methods of L-phosphinothricin: i) enzymatic hydrolysis the derivatives of L-phosphinothricin (e.g. hydrolysis of bisphosphonate by protease), ii) enzymatic resolution of the precursor of phosphinothricin (e.g. enzymatic resolution of dialanyphosate ethyl by α-chymotrypsin), iii) asymmetric synthesis of enzymes (e.g. asymmetric synthesis of 4-(methylhydroxyphosphinyl)-2-oxobutyric acid by glutamate hydrogenase).

Fig. 2 Examples of the biosynthesis methods of L-phosphinothricin

Our L-Phosphinothricin

Our L-phosphinothricin is produced through the combination of chemical and biological synthesis methods. Compared to the common two-step method: i) synthesis of D, L-phosphinothricin through Strecker reaction, ii) enzymatic resolution), the new method takes a conventional compound as raw material instead of D, L-phosphinothricin. With this method, the reaction steps are shortened, and the use of highly toxic compounds is avoided. What’ more, coenzymes self-sufficient recycling systems are used in the biocatalytic process. Basic properties of our L-phosphinothricin are listed as followings:

Alfa Chemistry is a professional supplier of biosynthetic L-phosphinothricin. For high quality products, professional technical service, use suggestion and latest industry news, please feel free to contact us.

References

1. Zhou C, Luo X, Chen N, Zhang L, Gao J. C-P Natural Products as Next-Generation Herbicides: Chemistry and Biology of Glufosinate. J Agric Food Chem. 2020 Mar 18;68(11):3344-3353.
2. Domingos L, Desrus A, Même S, Même W. L-Phosphinothricin modulation of inwardly rectifying K(+) channels increased excitability in striatal medium-sized spiny neurons. Arch Toxicol. 2016 Jul;90(7):1719-27.

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